Re: [ROOT] get elements of a TMatrixD

From: Fons Rademakers (Fons.Rademakers@cern.ch)
Date: Thu Mar 14 2002 - 10:55:46 MET


Hi Nicolas,

  note however that the elements in the TMatrix are layed out in a
coulmn-wise fashion like in FORTRAN. Just getting fElements and mapping
it to a two dimensional C/C++ array will not work.

Cheers, Fons.




On Thu, 2002-03-14 at 08:40, Rene Brun wrote:
> Hi Nicolas,
> 
> I agree with your comments. Too much data hiding in the design of this class.
> Would you be willing to send the few lines (getters) that you would like to see
> in TMatrixD, also TMatrix and TVector(D) ?
> 
> Rene Brun
> 
> Nicolas Produit wrote:
> > 
> > Hi,
> > 
> > I have to initialise a TMatrixD from an array of double
> > and also to give all the element of a TMatrixD to a routine that expect
> > a double* (for example to sort all the elements of a matrix)
> > There is no way of acessing FElements (private and no method to access it).
> > I see that &x(0,0) is not FElements but just the adress of a copy of its
> > content.
> > 
> > Is it possible to have a method that return FElements?
> > What will be also very handy for me is to be able to use a TMatrix as a
> > TArray because my structure is at hte same time a matrix and an array.
> > So an operator [int] with just one element accessing
> > the elements of matrix from 0 to GetNoElements()-1 will be very usefull.
> > I would be able to use a loop on x[i] rather then an apply method wich
> > is much more complicated.
> > 
> > Thanks
> > 
> > --
> > Nicolas Produit
> > INTEGRAL Science Data Center    Phone:  +41 22 950 91 40
> > 16, Chemin d'Ecogia             Fax:    +41 22 950 91 33
> > CH-1290 Versoix                 www:    http://isdc.unige.ch/
-- 
Org:    CERN, European Laboratory for Particle Physics.
Mail:   1211 Geneve 23, Switzerland
E-Mail: Fons.Rademakers@cern.ch              Phone: +41 22 7679248
WWW:    http://root.cern.ch/~rdm/            Fax:   +41 22 7679480



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